Error: Unable to get the Glance service version.

[Liyingjun]

When accessing images page, the following error raised:
error invoking apiclient
Traceback (most recent call last):
  File "/opt/stack/horizon/openstack_dashboard/api/rest/utils.py", line 131, in _wrapped
    return JSONResponse(data, json_encoder=json_encoder)
  File "/opt/stack/horizon/openstack_dashboard/api/rest/utils.py", line 67, in __init__
    cls=json_encoder)
  File "/usr/local/lib/python2.7/dist-packages/oslo_serialization/jsonutils.py", line 190, in dumps
    return json.dumps(obj, default=default, **kwargs)
  File "/usr/lib/python2.7/json/__init__.py", line 250, in dumps
    sort_keys=sort_keys, **kw).encode(obj)
  File "/usr/lib/python2.7/json/encoder.py", line 209, in encode
    chunks = list(chunks)
  File "/usr/lib/python2.7/json/encoder.py", line 434, in _iterencode
    for chunk in _iterencode_dict(o, _current_indent_level):
  File "/usr/lib/python2.7/json/encoder.py", line 408, in _iterencode_dict
    for chunk in chunks:
  File "/usr/lib/python2.7/json/encoder.py", line 443, in _iterencode
    for chunk in _iterencode(o, _current_indent_level):
  File "/usr/lib/python2.7/json/encoder.py", line 440, in _iterencode
    raise ValueError("Circular reference detected")
ValueError: Circular reference detected

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/444750

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/444750
Committed: https://git.openstack.org/cgit/openstack/horizon/commit/?id=942fa3d7cdf74f118b3cfadaf09820bbe57211af
Submitter: Jenkins
Branch: master

commit 942fa3d7cdf74f118b3cfadaf09820bbe57211af
Author: liyingjun <email address hidden>
Date: Tue Mar 14 10:48:38 2017 +0800

    Fix the return value for glance get_version

    The VERSIONS.get_version returned a Version object instead of a string,
    it will raise ValueError: Circular reference detected when json encode.

    This issue was introduced by commit
    834722cf8af7b3471e9c7234da0bac8669025ca2

    Change-Id: Ib41b2f7e77ac49911e9d5a4e129047f941bf5d24
    Closes-bug: #1672291

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/horizon 12.0.0.0b1 development milestone.